From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: What's the best (i.e. least bad) way to re-redisplay? Date: Tue, 24 Aug 2021 10:56:07 +0000 Message-ID: References: <83fsv0vts5.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="12393"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Aug 24 12:56:53 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mIU6v-0002xP-AH for ged-emacs-devel@m.gmane-mx.org; Tue, 24 Aug 2021 12:56:53 +0200 Original-Received: from localhost ([::1]:44074 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIU6t-0004Xa-7b for ged-emacs-devel@m.gmane-mx.org; Tue, 24 Aug 2021 06:56:51 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34150) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIU6I-0003nz-GU for emacs-devel@gnu.org; Tue, 24 Aug 2021 06:56:14 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:57809 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1mIU6F-00080P-CB for emacs-devel@gnu.org; Tue, 24 Aug 2021 06:56:14 -0400 Original-Received: (qmail 37023 invoked by uid 3782); 24 Aug 2021 10:56:08 -0000 Original-Received: from acm.muc.de (p4fe1570c.dip0.t-ipconnect.de [79.225.87.12]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Tue, 24 Aug 2021 12:56:08 +0200 Original-Received: (qmail 4440 invoked by uid 1000); 24 Aug 2021 10:56:07 -0000 Content-Disposition: inline In-Reply-To: <83fsv0vts5.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:272903 Archived-At: Hello, Eli. On Mon, Aug 23, 2021 at 22:35:22 +0300, Eli Zaretskii wrote: > > Date: Mon, 23 Aug 2021 18:41:59 +0000 > > From: Alan Mackenzie > > I envisage a situation where an identifier is identified as a type during > > jit-lock fontification, and thus font-lock-type-face needs to be applied > > to all occurrences of this identifier. > > The problem is, there will be occurences in the foreground window before > > the one which triggered the fontification. Redisplay will already have > > passed this earlier buffer position. So I need to trigger another > > redisplay immediately after the current one. > > What is the least bad way of doing this? > You mean, the same identifier is somewhere in the same window-ful, but > before the position where you suddenly decided your previous > fontification was incorrect? (Why is this a reasonable scenario, > btw?) For example, in a C file we have a function prototype without parameter names: fooMain (foo); , and later on this gets fleshed out: fooMain (foo bar) { .... } The first occurrence will get fontified as a function call, I think. Only when we pass the second occurrence do we see foo must be a type. > > Currently, I'm thinking of something like the CC Mode fontification > > functions setting a flag, and a repeating timer function testing this > > flag every 0.025s, say, and triggering a redisplay if it's set. > Why not simply call a one-time timer function that runs > jit-lock-force-redisplay, when you decide that you need to refontify? > jit-lock.el already does that in some cases. I see no reason to have > a periodic timer and a flag, because the same code that sets the flag > could instead arm a one-time timer. Thanks, that's exactly the answer I was asking for. :-) I didn't know about jit-lock-force-display. > > One problem is knowing whether or not redisplay is currently active. Is > > there a simple way to do this in Lisp? (I know there is in C.) > I don't understand your problem here. Timers cannot run while > redisplay works, because timers are only run by the main loop. So > when a timer runs, redisplay by definition isn't. That was going off on a bit of a tangent. If the above situation occurs when we know we're not already in redisplay, we could simply call redisplay without using a timer. I suppose it's not really that important. -- Alan Mackenzie (Nuremberg, Germany).